(1) Technical Field
This invention pertains to a well system utilizing two flow conduits. The invention particularly pertains to a system useful in a well produced by gas lift for preventing flow of lift gas through a secondary well tubing to surface and production flow to surface through a primary well tubing.
(2) Background Information
Prior annular safety systems for gas lift wells utilized complicated and expensive assortments of packers, sidepocket mandrels, gas lift valves and safety valves. These annular safety system installations required pressurized gas or production in tubing casing annular flow passages with inaccessible safety valves positioned below one or two packers. Well servicing tools could not be lowered into some of the installations on wireline because of restrictions or abrupt offsets in the flow conduits. The annular safety system of this invention requires no gas lift valves, side pocket mandrels and only one packer. Pressurized lift gas or production does not flow in the tubing casing annulus. All safety valves used are above the only packer required and are easily retrievable. Full bore well tubings are utilized permitting wireline servicing tools to be lowered through the production tubing.